Electronic tube clamp and shield



l.. R. WOODS 2,766,020

ELECTRONIC TUBE CLAMP AND SHIELD Filed Aug. 28, 1953 gpg. 50 zig?. 6'.sa 1o 1) 11) f22 6 n W/ 31 I5' I: 36

LEROYRALPH wooDs, JNVENToR.

HUEBNER, BEEHLER, woRREL a HERznG.

ATTORNEYS.

United States Patent Office 2,700,020 Patented Oct. 9, 1956 2,766,020ELECTRONIC TUBE CLAMP. AND SHIELD Leroy Ralph Woods, Whittier, Calif.,assignor to International Electronic Research Corporation, Burbank,Calif., a corporation of California Application August 28, 1953, SerialNo. 377,080 9 Claims. (Cl. 2517-263) The invention relates to devicesfor securing electronic and similar types of vacuum tubes, which devicesserve also as a means of cooling the tubes by conducting heat therefromand also as cushions so as to minimize the effect of high frequencyvibration on the tubes.

Two outstanding essentials in the employment of electronic tubes havebeen the provision of tube clamps capable of securely mounting the tubesin a selected location and devices for conducting away from the tubesheat generated during their operation. New developments in certainfields and particularly the lields devoted to aircraft and guidedmissiles have produced vibration conditions of far greater amplitude andintensity than previously experienced. Greater demands upon theperformance of such electronic tubes have also necessitated moreeflicient means for conducting heat away from the glass exterior so asto more uniformly and more thoroughly cool the tubes.

Spring clips have often been resorted to for holding tubes in place.These have a number of objectionable features, one being that springmetal, when heated to temperatures frequently experienced in thisparticular lield, tends to lose its resiliency and elfectiveness.

It has also been kno-wn that glass is a relatively poor conductor ofheat and for this reason tube clamps designed so as to grip the glass atscattered locations fail as a heat conducting medium in that, althoughheat may be conducted very rapidly away from those points on the glasstouched by Vspring elements o r fingers, there is suiicient heatremaining in the glass at locations between the points gripped by thefingers that excessive strains are set up resulting ultimately incracking and failure of the tubes. With further respect to the new andhighly intensive vibration conditions it has been found that on manyoccasions vibrations set up a resonant condition which greatlyaggravates the objectionable effects normally experienced in thepresence of very high frequency vibrations.

It has further been found that, particularly in flat press tubes wherethe area around wires emerging from the tubes is pressed into a flatform, normally unequal expansion between glass and the metal of the wirehas caused a condition making it very necessary to cool tubeseffectively at that point.

Efforts to improve the contact areas between the tube clamp and theglass have met with indifferent success partly by reason of the factthat relatively large tolerances are permitted in bulb diameter.Tolerances iu surface areas have also been permitted to the extent thatvery frequently seams are present, high spots, and conditions ofout-of-round form sufficient to considerably impair a close iit of theshield around the tube. This often results in a gradual diminution ofthe grip of the clamp on the tube until, after a period of use but longprior to exhaustion of the tube itself, the grip weakens and conditionsbegin to .accumulate requiring constant servicing.

( ood heat .conductors .can be found which include aluminum yalloys and.spring silver. Although both of Athese metals are highly effective as aheat-conducting medium, they nevertheless lose their effectiveness whenheated due to losing their temper and consequently their snug grip uponthe tube.

A great deal of trouble has been experienced from snapping tubes intothe spring type clamps. The snap.- ping is su'icient often to start aslight strain not iinine-Y diately detachable but which after use undervibration conditions ultimately contributes to fracturing of the tube atan inopportune time.

It is therefore among the objects of the invention to provide a new andimproved tube. clamp and heat-conducting shield device which is capableof uniformly cooling an electronic tube on which it may be used.

Another object of the invention is to provide a new and improved tubeclamp and heat-conducting shield capable of operating at a lowtemperature gradient between tube and shield.

Still another object of the invention is to provide a new and improvedconstruction for a tube clamp and heatconducting shield such that themetal best able to conduct heat may be used for that purpose withoutimpairing the ability of the clamp to maintain a tight grip upon thetube.

Still another object of the invention is to provide a tube clampingmeans consisting of a relatively dead metal so associated with a springclamp that the dead metal is retained in place securely and uniformly byspring pressure which, because of the absence of heat in the springclamp, will not weaken and deteriorate, thereby to diminish the eiciencyof the tube installation.

Still further among the objects of the invention is to provide a new andimproved tube clamp and heat-conducting shield which is especially welladapted to the clamping and cooling of flat pressed miniature andsubminiature tubes.

Also included among the objects is to provide a new and improvedcushioned clamp which permits insertion of the tube without undue strainupon the glass and which permits removal of the tube from the clamp withequal ease.

accompanying drawings.

In the drawings:

Figure l is a side elevational view of one form of the tube clamp andheat-conducting shield device in place upon a at press tube.

Figure 2 is a vertical end elevational view of Figure l.

Figure 3 is an exploded view showing a tube and showing parts of thetube clamp and shield device in which they are advanced into contactwith the tube.

Figure 4 is a cross-sectional view taken on the line 4 4 of Figure l.

Figure 5 is a longitudinal sectional View of a Subminiature tube whereinthe tube clamp and shield device is illustrated with a modified type rofliner. l

Figure 6 is a vertical sectional view taken on the line 6-6 of Figure 5.

Figure 7 is a longitudinal View partially in section showing a form ofthe device applied to a button type tube.

Figure 8 is a fragmentary view of the innermost liner element employedin the form illustrated in Figures 5 and 6.

In a form of the device chosen to illustrate the invention there isshown a llat press tube 10 conventional in subminiature type tubes whichconsists of a cylindrical portion V11 and a flat press 12. The at pressproduces opposite substantially parallel at faces 13 and 14 at the endof which is a transverse bead 15 from which protrude wires 16.

For holding a tube of the flat press type there are provided, asillustrated in Figure l, two principal elements comprising a chassis 17and a clamp 18. These elements are shown in assembled condition inFigures 1 and 2 and separately in Figure 3.

More particularly the chassis is built from a dead metal. This deadmetal is preferably very soft -silver initially in sheet form which maybe pressed by means of a die into the form illustrated in Figures l, 2and 3. The chassis as there shown is provided with protrudingcongurations 19 spaced longitudinally one from another and extendingsubstantially throughout the length of the chassis. These protrudingconiigurations extend across the chassis as is observable in Figure 4 soas to provide a series of flat base elements by means of which thechassis is supported upon some appropriate supporting surface. if thesupporting surface be a metal, the chassis may readily be silversoldered or silver brazed to the base.

The chassis includes a pair of semi-cylindrical side walls 20 and 21which can be folded around the cylindrical portion 11 of the tube afterthe tube is placed in the chassis. The semi-cylindrical walls are madeof such width that they almost meet along a longitudinal meeting line22. It is of interest to note that the protruding congurations 19terminate on opposite sides in rounded ends 23 and 24 which stand out aslight distance from the exterior wall of the cylindrical portion of thetube. The congurations may be described as transverse ribs comprising abottom support for the chassis.

At one end of the chassis is a tongue 25 dished to a limited extent forreception `of the end of the cylindrical portion of the tube where itjoins the flat press. The tongue turns upwardly to a transverse roundedcontact 26 which is adapted to have the lower face 14 of the flat pressrest thereon. Ordinarily the end of the chassis opposite the end atwhich the tongue is located is open.

After a tube has been set in the chassis and the semicylindrical sides20 and 21 folded around it, the clamp 18 may be applied. The clamp isconstructed of spring material. This clamp has a portion 30 slightlycylindrical so as to fit the exterior contour of the semi-cylindricalwalls 20 and 21. Along each side of the portion 30 is a series offingers 31 spaced longitudinally from each other and formingtherebetween a series of spaces 32. The fingers continue to carry outthe semi-cylindrical form of the clamp.

At one end of the clamp, namely, the end corresponding to the end atwhich the tongue 25 is located on the chassis, there are provided aseries of spring legs 33 spaced laterally one from another and extendingendwise and downwardly to a location where rounded ends 34 of the legsare adapted to engage in the face 13 of the fiat press.

It will be noted further that the spring lingers 31 also terminate inrounded ends 35 and that these ends are adapted to iit between therounded ends 23 and 24 of the protruding configurations on the chassis.By fitting thus. snugly the fingers prevent endwise shifting of theclamp relative to the chassis as well as being depended upon to pressthe soft metal semi-cylindrical walls 20 and 21 into snug uniformcontact with the glass exterior wall of the tube.

Because of the soft character of the semi-cylindrical walls 20 and 21the metal of the walls is adapted to and does conform to irregularitiesin the exterior surface of the glass wall of the tube. The ngerstherefore serve as a means of conforming the soft metal of the chassisinto efiicient heat-conducting relationship to the glass of the tube aswell as serving to anchor the tube in its bed or position in thechassis. From this description it will be apparent that the tubes aremerely laid in the soft silver chassis without there being any snappingof the tube in place which would otherwise tend to sct up a strain inthe glass.

After the chassis walls have been wrapped around thc glass, applicationof the spring iingers 31, even though they might be snapped into place,does not set up any strain in the glass of the tube because of the factthat the soft metallic semi-cylindrical walls 26 and 21 absorb the shockof snapping the spring fingers into place.

Further by reason of pressing the tongue 25 into snug engagement withthe flat press where it is held in snug engagement by the legs 33, theflat press is provided with a means of having heat conducted therefromwhich as a consequence materially improves the cooling of the tubeparticularly at the critical point where the wires are embedded andemerge.

in a modiiied form of the invention illustrated in Figures 5 and 6 thereis provided a liner or what may be aptly described as a cushion liner 36which may advantageously comprise an initially relatively flat sheet ofwaiiie embossed silver. This is a material frequently in theneighborhood of about .003 inch in thickness but wherein the effectivethickness due to the wafiie grid effect may be somewhat greater. Detailsof the cushion liner are shown in Figure 8.

The cushion liner is constructed of such width that it willsubstantially surround the cylindrical portion 11 of the tube leavingonly a line 37 of separation.

The positioning of the liner is illustrated to good advantage in Figures5 and 6. The length of the liner may be the same or slightly greaterthan the length of the cylindrical portion 11 of the tube. When appliedthe liner is initially wrapped around the tube and then the tube withthe surrounding liner is rested in the chassis as an object might berested in a cradle. The semi-cylindrical sides 20 and 21 of the chassisare then bent around the cushion liner and ultimately the clamp 1S isapplied over the chassis semicylindrical side walls in the same manneras was initially described in connection with Figures l, 2 and 3. Thisbrings the spring fingers 31 into contact with the exterior of thechassis and thereby adding to the force of pressing the liner intoconformation with any irregularities that may exist on the exterior ofthe glass wall.

An optional and convenient means of securing the chassis 17 to anappropriate mounting is illustrated in the modied fonn of Figures 6 and7. For this purpose there is provided a channel-like clamp or elongatedstaple S0 having a flat web 51 silver soldered or otherwise attached tothe coniigurations or transverse ribs 19 of the chassis. At each side ofthe web is a leg 52, adapted to be bent as shown by the dotted position52' in Figure 6. The clamp thus described is an effective medium for usein mounting the chassis on one of the commercial forms of fibre mats inwhich slots may be cut for reception of the legs during the mountingoperation. The clamp is one well adapted to mechanical assemblyoperations.

On those occasions where the tube clamp and shield device may be calledupon to receive and mount a subminiature type tube of the so-calledbutton type, such as the tube 4i) of Figure 7, some slight modificationmay be found advantageous. The button type tube usually features anannular bead 41 at the pressed end through which Wires 42 dispersedcircumferentially about the end protrude. Frequently there is acylindrical portion 43 at the other end of which may be a cap-likeportion 44 adjacent a tip 45.

If the button type tube should have variations in the exterior contoursuch as those variations herein suggested or other variations due toroughness or a wide tolerance allowance in circumference, neverthelessthe tube clamp and shield device may be counted upon to functionetlciently and successfully. A chassis 46 substantially similar to thechassis 17 is employed except that there is omitted the tongue 2S andits transverse rounded contact 26. The chassis as previously noted isconstructed of soft metal, soft silver being especially applicable, sothat the metal of the chassis will conform to the irregularities of thesurface of the tube.

A clamp 47 is employed having the same general shape and configurationas the clamp 18 except that the legs 33 are omitted. Fingers 48 extendalong both sides and are spaced apart as previously noted by spaces 49therebetween. The fingers iit into the usual spaces between protrudingconfigurations 19 of the chassis as shown in Figure 7 and of the samegeneral form as shown and described in connection with Figures 1 through6, inclusive.

Constructed as described the soft metal of the chassis can sustain avery considerable amount of heat and by reason of the fact that it canbe constructed of the most eicient heat-conducting metal, the chassis isextremely eicient in conducting heat away from all sides of the tube andalso from all portions of the tube surface. Continued heating orcontinued alternate heating and cooling conditions do not affect theefficiency in any adverse way. Such effect as might be experienced ismore in the nature of a still closer conformation of the chassis to theglass as the installation continues in use. When the cushion liner 36 isemployed the liner may be constructed of somewhat thinner material thanthe chassis can be constructed of and consequently the liner to a degreeeven greater than the chassis is adapted to conform to suchirregularities as may exist due to variations in tolerance, seams,protrusions and other irregularities on the tube surface.

Whether the chassis be used alone or in company with the liner, the softcharacter of the metal has a very marked effe-ct in dampening vibrationsand destroying the tendency of the tube clamp to experience resonantconditions. This is as true of extremely high Vibrations of thesupersonic type as in ordinarily high vibrations heretofore experiencedin aircraft and guided missiles. Uniform pick up of heat from allportions of the glass virtually eliminates mechanical and heat strainsin the glass, even though portions of the glass may be heated toconsiderably higher temperatures than closely adjacent portions. Furtherby reason of the fact that the spring fingers of the clamp are notdepended upon to contact the hot surface of the glass and further byreason of the fact that the chassis may be constructed of a materialhaving greater heat-conducting qualities than the spring clamp, thesespring fingers do not absorb a sufficient amount of heat to modify theirtemper and springy character. ln consequence they maintain their initialiirm grip, holding the sides of the chassis in place despite cxtremeconditions in temperature and vibration expected to be encountered inuse. The possibility of the tube loosening from its mounting istherefore materially minimized.

There has been therefore disclosed herein a highly eiiicient tube clampand shield device which combines the qualities of extremely eflicientcooling with vibrationresistant qualities sufficient that the device maybe depended upon to remain securely in place upon any suitable face andto securely hold the tube mounted therein in its proper position.

While I have herein shown and described my invention in what l haveconceived to be the most practical and preferred embodiment, it isrecognized that departures may be made therefrom within the scope of myinvention, which is not to be limited to the details disclosed hereinbut is to be accorded the full scope of the claims so as to embrace anyand all equivalent devices.

Having described my invention, what l claim as new and desire to secureby Letters Patent is:

l. A clamp and heat-conducting shield device for electronic componentscomprising a chassis of dead metal corresponding in length to the lengthof a component and having protruding configurations along a bottomthereof presenting longitudinally spaced transverse ribs and havingsubstantially semi-cylindrical sides adapted to y remote from the ribs,a tongue fold over the component, and a clamp of spring metal comprisinga semi-cylindrical portion corresponding in length to the length of thechassis, said clamp having a series of longitudinally spaced springfingers on each side of the clamp adapted to extend around the lowerside of the chassis and into spaces between said ribs.

2. A tube clamp and heat-conducting shield device for electronic fiatpress tubes comprising ya chassis of dead metal corresponding in lengthto the length of la tube and having protruding configurations along abottom thereof and substantially semi-cylindrical sides adapted to foldover the tube, a tongue at one end of the chassis extending endwise andadapted to engage one side of the at press of the tube, and a clamp ofspring metal comprising a dished portion corresponding in length to thelength of the chassis, said clamp having spring elements at the sidesadapted to extend around the lower side of the chassis, and a springmeans extending from one end of the clamp adapted to engage the otherside of said flat press.

3. A tube clamp and heat-conducting shield device for electronic iiatpress tubes comprising a chassis of dead metal corresponding in lengthto the length of a tube and having protruding configurations along abottom thereof presenting longitudinally spaced flat faced transverseribs and having substantially semi-cylindrical sides adapted to foldover the tube to a longitudinal meeting line along the top. a tongue atone end of the chassis extending endwise and adapted to engage one sideof the flat press of the tube, and a clamp of spring metal comprising asemicylindrical. portion corresponding in length to the length of thechassis, a series of longitudinally spaced spring fingers on each sideof the clamp adapted to extend around the lower side of the chassis andinto spaces between said ribs, and a spring element extending from oneend of the clamp to a position adapted to engage the other side of saidflat press.

4. A tube clamp and heat-conducting shield device for electronic fiatpress tubes comprising a chassis of dead metal corresponding in lengthto the length of a tube and having protruding configurations uniformlyspaced along a bottom thereof presenting substantially flat facedtransverse ribs having spaced rounded ends and having substantiallysemi-cylindrical sides adapted to fold over the tube to a longitudinalmeeting line along a side at one end of the chassis ribs extendingendwise and outin a transverse rounded contact adapted to engage oneside of the fiat press of the tube, and a clamp of spring metalcomprising a semi-cylindrical portion corresponding in length to thelength of the chassis, a series of longitudinally uniformly spacedspring fingers on each side of the clamp adapted to extend around thelower side of the chassis and into spaces between said rounded ends ofthe configurations, whereby to press the chassis uniformly intoheat-absorbing contact with the tube, and a series of spring legsextending from one end of the clamp having rounded ends adapted toengage the other side of said tlat press.

5. A clamp and shield device for electronic components comprising achassis of dead metal corresponding in length to the length of acomponent and having high heat-conducting characteristics, said chassishaving a bottom and semi-cylindrical side walls adapted to extend aroundthe component, an inner liner of initially flat dead metal materialadapted to lie between the exterior surface of the component and theinterior surface of said chassis and adapted to extend throughout thecylindrical portion of the component, and a clamp of spring metalcomprising a dished portion corresponding in length to the length of thecomponent, said clamp having spring elements at the sides adapted toextend partly around the lower sides of the chassis, whereby saidchassis and the inner liner are pressed into intimate contact with theexterior wall of the component.

on the side adjacent the wardly and terminating 6. A clamp and shielddevice for electronic tubes comprising a chassis of dead metalcorresponding in length to the length of a tube and having highheat-conducting characteristics, said chassis having longitudinallyspaced protruding configurations on one side forming a bottom andsemi-cylindrical side walls extending to a separation line along oneside, an inner liner of initially at embossed dead sheet metal materialadapted to lie between the exterior surface of a tube and the interiorsurface of said chassis and adapted to extend throughout the cylindricalportion of the tube, and a clamp of spring metal comprising asemi-cylindrical portion corresponding in length to the length of thechassis, said clamp having a series of longitudinally spaced springlingers adapted to extend partly around the lower sides of the chassisand between the coniigurations, whereby said chassis and the inner linerare pressed into intimate contact with the exterior wall ofthe tube.

7. A tube clamp and shield device for at press electronic tubescomprising a chassis of dead metal corresponding in length to the lengthof a tube and having longitudinally spaced transverse configurations onone side forming a bottom and semi-cylindrical side walls on the bottomadapted to extend around the tube, an inner liner of initially flat deadmetal material `adapted to lie between the exterior surface of a tubeand the interior surface of said chassis and adapted to extendthroughout the cylindrical -portion-rofwthetube, and a clamp of springmetal comprising a semi-cylindrical portion corresponding in length tothe length of the tube, said clamp having spring elements adapted toextend partly around the lower sides of the chassis, whereby saidchassis and the inner liner are pressed into intimate contact with theexterior' wall of the tube, a tongue at one end of the chassis extendinggenerally endwise into the flat press at one side of the tube and springmeans on a corresponding end of the clamp extending generally endwiseinto the at press at the other side of the tube.

8. A clamp and heat-conducting shield device for electronic componentscomprising a chassis of dead metal having a pocket conforming in generalto the size and shape of the component and having side Walls of breadthadapted to be pressed to positions overlying and substantiallysurrounding said component, a base-contacting portion comprising part ofsaid chassis and having an area of the base-contacting portion adaptedto be anchored to the base, and a clamp of spring metal cornprising adished portion corresponding in size and dimension to the exterior ofthe chassis, said clamp having separate longitudinally spaced springelements at side edges thereof, said spring elements in assembledposition extending around the side walls and beneath the chassis and inresilient contact therewith and separated by said chassis from directcontact with the component whereby to urge said chassis into heatdissipating cor/1- tact with the component.

9. A clamp and heat-conducting shield device for electronic componentscomprising a chassis of dead metal corresponding in one lineal dimensionto the corresponding dimension of the component and having a pluralityof lineally spaced conligurations defining engaging areas for said clampon each opposite side, said chassis having sides of breadth adapted tosubstantially envelope sides and top portions of said component in anenvelope of; said dead metal, and a clamp having one lineal dimensioncorresponding to the first identied lineal dimension of said chassis,said clamp having a series of lineally spaced spring elements on eachside integrally connected by a web portion and resiliently contactingsaid chassis, said clamp extending throughout substantially more thanhalf the perimeter of said chassis and adapted to engage said lineallyspaced areas on said chassis whereby to press said dead metal intoengagement with the component.

References Cited in the lile of this patent UNITED STATES PATENTS2,019,939 Suller Nov. 5, 1935 2,494,881 Kost Ian. 17, 1950 2,662,220Saari Dec. 8, 1953 2,668,933 Shapiro Feb. 9, 1954 2,701,866 Chapman Feb.8, 1955

